This invention is concerned with improving the performance of high wear agricultural tools which form furrows or slices in the soil such as agricultural fertilizer knife assemblies and hoe drill shoes.
Agricultural tools such as fertilizer knives and hoe drill shoes, more fully described in U.S. Pat. Nos. 3,919,951; 4,132,181 and 4,750,440, typically include a soil opener member. Depending upon the particular application, the soil opener member may be in the form of a shoe member or a hoe member capable of passing through the soil. The soil opener member, generally streamlined in configuration and having a pointed leading end, provides a furrow for the passage of substances such as fertilizers, herbicides, fungicides, seeds and the like to the subsoil beneath the surface of the ground.
In operation, as the soil opener member advances, the pointed leading end penetrates the subsoil and the slicing edge of the member neatly divides the subsoil providing a furrow or slice of a uniform symmetrical V-shape having firm smooth sidewalls. Because of the penetrating, smoothing and firming action rendered by the soil opener member, a very well defined V-shape furrow is formed in the subsoil so that material discharged through a tube following behind the soil opener member may be uniformly positioned within the furrow.
It will be appreciated that as the soil opener member advances within the subsoil, the soil opener member encounters various high wear objects such as high silica soil, rocks, debris and the like. These high wear objects have a tendency to blunt the point of the soil opener member thereby producing a furrow having uneven and/or rounded sidewalls full of loose clods of soil. Accordingly, any material which is placed in the furrow is necessarily placed in random orientation and/or in an inappropriate position. In addition, it will be appreciated that a soil opener member having a blunt leading end has a tendency to "bull doze" the soil producing random air cavities within the subsoil and compressing and compacting the soil thereby generally destabilizing the agricultural tool. In view of the foregoing, there is a significant need for an improved agricultural soil opener member that resists wear, is durable in construction, and is economical to manufacture.
To alleviate the aforementioned problems I have invented a novel self sharpening pyramidal shaped insert of a refractory hard metal for use as a leading penetrating and slicing element of an agricultural soil opener member for applying material beneath the surface of the ground. The insert of the present invention inhibits wear of the soil opener member thereby contributing to proper soil flow, V-shape furrow formation and improved material placement as the soil opener member slices a furrow in the subsoil.